To him



I PATENTED 00T 11 1870 Witnesses:

To all whom it may concern:

sriLr AND ciioiion W.

JoHN U. L. 'rEEMsTEa or oiinENoiisrLn, isolana, Assieme fro HIM- soo-Tfr, or sAMnrLAoE.

Letters Patent No. '-108,245, dated October 11, 1870.v i

' IMPROVEMENT iN CASTiNG DENTAL PLATES.

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Be it known that'I, Joint U. L. Fnisnsrnn., of Greencastle, in the county of lii'tiia'rnaud, State 'of Indiana', have invented a uewand improved .Method ot' Casting Dental Plates; and I do hereby declare that the Afollowing is a full and exact.. de'scription ol the same, reference being had to the accompanying draiviugaud .to the letters of' reference marlicd'tliereon.v

' This invention consists- 1 First, in a method of" casting dent-al pates, the novelty. o'fwhich lies in'tliefeinployment ofgas'in ste'atlot air :to force the molten.A metal ties of "the mold; and. A I d '"Secoiihi'uthe specilic construction Aand ariangement of theapparatiis for carrying rny method'iuio etl"ect.

lathe 'drawing- 'proreuapparatns shown partially iii section; and

To@enable othersy skilled iu the art to make and Vuse.'my'invention, I will now' proceed t'o-describe fully its construction-,and maui'ieriot' operation. f

The vmohljis formed iu any suitable naniier, confined iii a 4flask of proper form;v

Connecting with" t h'e'i lask is a reservoir for the molten metal, and connecting-with this reservoir. is a pipe.'througli.whieli deoxidizing gasis conducted from n suitable retort;v

. The molten metal is admitted into tho flask :it the Impar-.time by any suitable means, and at 'the same time the-"a's'is also admitted, so that the metal is liorced..into every minute cavity of the mold by the elastic pressure of the gas.

vThe' means employed for carrying this method of casting-into eleet will now be described.

A represents a flask constructed in three piu-ts, a (daz, and -proifided with a vent tube, c.

' `fldhis flask, when in position, rests upon the vertitrali'oids or standards a* a, and is held from displace- Vinem; by means of the stay-rod af", which rests upon the cross-bar P below, and pi'essesagaiust the crossbar c7 above,the latter being supported by means of the side'standaitls u e", as shown." The cross-bar c is rendered adjustable by nieaus and is ol' screw-rods upon the standards a", in order that the'V stay-rod a5 may beeasily inserted at any time, as I'nay be desired.-

A crib, of suitable construction, with proper easiu place, or removed ings, is placed aboutthe flask,- to eeiitaiircharcoal, or

other combustibles, for properly; heating it.

B represents the reservoir, in which the molten I v and th'us Figures. 2, 3, and 4 represent views of teeth; as

.manipulated by nie; been cast 'under metal is placed.' It is provided with a plug-rod, 11, and stopper bl.

in which the gus is generated. It. is'conneetetbto the reservoir B by ineans of the pipe. c, provided with Lily-means of this construction I ani `ena-bled, when cated by the prevent further action iugthe retort.

I am aware thatl aluniinii'm plates for teeth harp pressure of air, butfa great advantage is obtained'by the. substitution of a deox'idiziug gas:

First, because the'niechaliical force desired oan be readily obtained by the chemical action which forms thel gas by simply bringing tlio necessary elements into contact, the employment ofjair requires delicate and expensive apparatus. v

gauge, to mise the zinc ont ot' the acid,

deoxidizing kept'cleau and bright, and is oxide, which always .forms ou exposed to the action of the air, and, consequently, a more perfect Iuuioii -is formed between the parts as the mold becomes lilled.. llhe operation ofcasting will now be described: .lhe veiitpipo` :iud -1'eseivoii'1'iipe aresecured iu position, and the ilaskispla'ced upon the standards a chas shown, and secured in place by means of lthe stay-rod a", as before described.

Heat is now applied in anysuitable manner until the flask is hea-ted to about 900 lfahi'enheit, which is a dull red heat.v

The reservoir B is now heated, of course, to the melting point oi' iiliii'niuuln. 'lhe melted metal is now poui'ed therein, the stopper being removed thei'iit'rom, is contained therein. f d

The stopper being replaced to prevent the of gas, the plug-rod is raised, and, :it the stop-cock c' is turned. 4 The result of this operation is that the hot metal escape the saine time,

is forced by the pressure of the gas in the retort,

(l represents a retort, of any suitable construction,

the stop-'cock el, and haring also the gauge c2 to iugas may be generated in use hydrogen, which is by placing' zinc therein, a

withoi'it further 'care or attention, while.

Second, by the Veiuployinent 'of hydrogen or other gas,' the 'suiface of the fused metal is clear from the filth ot'f the surface when it is until a sulicieut supply necessarily obtained.

into every cavity of the mold, and a' perfectcastirg is 'Y As soon as this operation is' oompietd .the lowerI part of the' grate is removed and theire cleaned .away to permit theask t cool, while the fire above keeps the reservoir sufficiently heated to enable it to discharge hot m'ctal'linto the ,flask-toiill th space madel vacant by contraction.- hen the flask is suf-f icieLtiy cool-the piatevmayheremoved.

and flask A, whenithe piu-ts are zii-ranged as described-for-the purpose set forth.

This 'specification signed and witnessed. this '18th -R. E. HAWLEY, J os-EPH S. MCOLARY.

gauge' c2, pipe c with cock c1, reservoir B with'rod b, 

